1. Field of the Invention
The present invention relates to a door control device for either resiliently maintaining a door closed or open a predetermined amount depending upon which side of overcenter the door is manually positioned, and more particularly relates to such a door control device for compartments or cabinets such as compartments on a fire truck or the like.
2. Description of the Prior Art
In general, it is important that the doors on fire truck compartments or the like be easily and quickly opened and closed with one hand, and remain in the selected position until manually shifted to the other position. When fighting a fire, the fire truck may from time to time be driven from one location to another and it is desirable that an open compartment door be closed by a fireman before movement of the vehicle to prevent articles from falling out of the compartment. This door closing should be achieved rapidly and preferably by merely slapping the door past dead center. The door control device should also take up as little space as possible in the compartment especially in the area of the compartment opening. Known control devices used with fire truck components are objectionable because they either require two hand operation and/or are large and bulky and include many costly pieces.
The following patents disclose door control devices for doors of different types.
The U.S. Pat. No. 2,220,766 to Hubbs is pertinent in that it operates on the overcenter princple and has an open door position at 90.degree.. The patent discloses a door control device that includes a bell crank arm pivoted to the underside of a bracket secured within and to the roof of a compartment. The free end of the long crank arm is pivoted to a link that is pivotally attached to a door bracket. A tension spring is connected between the short arm of the bell crank and the door frame bracket. When the door is at its 90.degree. open position, the spring is disposed on one side of the pivot pin and urges the bell crank arm against an abutment on the link, maintaining the door open at 90.degree.. When pivoted 90.degree. to the closed position, the spring is on the other side of the pivot pin thereby resiliently holding the door shut. However, a stop flange is not provided on the mounting bracket that is engaged by an overcenter pivot arm when the door is moved to its open position. Also, the overcenter plane is not substantially parallel to the compartment opening as in the present invention but is normal to the opening thus requiring a bell crank rather than a straight pivot arm resulting in a rather large control device which accommodates a considerable amount of frontal area in the compartment.
The U.S. Pat. No. 2,453,831 to Croskey et al. which issued on Nov. 16, 1948 discloses a door check employing the overcenter principle. A transverse rod is secured to the roof of a truck and slidably receives a slide pivotally connected to one end of a link. The other end of the link is pivotally connected to a door bracket by a pin. A spring on the rod is compressed and the pivot pin is overcenter in one direction of an axis through the door hinge and the pin, thereby holding the door closed. When the door is opened, the door pivot pin is overcenter of the axis in the other direction and the spring holds the door open, past the 90.degree. open position and not at a predetermined position, since the door may be swung further open against the urging of the spring. The door check also accommodates considerable frontal area in the compartment.
The U.S. Pat. No. 2,569,806 to Dunlap which issued on Oct. 2, 1951 discloses a double action door holder which employs the overcenter principle and resiliently holds the door at a 90.degree. open position when at one end of its swing, and in its closed position at the other end of its swing. A push rod has one end anchored to the door by a screw eye and its other end is free. A single spring surrounds the push rod with one end anchored to the push rod at the screw eye and the other end anchored to the free end of the rod. A second screw eye is fastened to the door sill and slidably receives the rod. The screw eye is interposed between coils of the spring at the midpoint thereof. This patent is pertient to the extent that it discloses an overcenter door control device which holds the door at its 90.degree. position. However, the door can be forced further open by compressing the outer end of the spring, but when released it will return to its 90.degree. position. Because the door is not positively held from movement beyond its normal open position, strong gusts of wind which may be present when fighting fires are more apt to close the door as compared to the subject device since the springs permit the door to swing in both directions past its open position. Thus, gusts of wind which catch the door as it is moving toward the closed position will more easily close the door as compared to the subject device.
Also, it is apparent that the Dunlap door holder is quite large since it extends substantially the full length of the door.